Roller

ABSTRACT

The invention relates to a roller ( 1 ), in particular, a castor. The rotation of the running wheel of said castor and optionally the pivoting motion of the running wheel ( 12 ) may be fixed, by means of an operating shaft ( 20 ), which moves a control cam ( 19 ) through the roller ( 1 ), with an electric motor ( 37 ) acting thereupon for operation thereof. According to the invention, the functional roller operation can be embodied with a more advantage operation, a simpler construction, yet of secure operation, whereby the electric motor ( 37 ) acts on the operating shaft ( 20 ) by means of an electric motor shaft ( 39 ) using a toothed gear ( 38 ).

[0001] The invention relates to a roller, in particular a castor-typeroller, with the rotational movement of the running wheel and optionallythe pivoting movement of the running wheel being fixable, with anoperating shaft which passes through a control cam of the roller and onwhich an electric motor acts via a gear mechanism to operate it.

[0002] A roller which can be switched by means of a rocker pedal with aview to being able to fix the rotational movement of the running wheeland the pivoting movement is disclosed by U.S. Pat. No. 5,377,372. Thepedal extends in the center of the chassis of a movable bed. Thisproduces a quite complicated transmission mechanism with respect to therollers.

[0003] It is already known from DE-A1 43 18 546 to use an electric motorto control an operating shaft passing through a control cam of theroller. The electric motor and gear mechanism are aligned in such a wayas to extend a push rod, which turns the operating shaft via anarticulated pivot lever and consequently turns the control cam, by whichthe described functions are performed. Here, too, a not inconsiderablecomplexity is involved.

[0004] The object of the invention is to make the functionally relatedoperation of the roller more advantageous in terms of how it operates,more simple in terms of how it is constructed and nevertheless reliablein terms of its use.

[0005] This object is achieved in the first instance and substantiallyin the case of a roller with the features of claim 1, it being providedthat the electric motor acts on the operating shaft by means of anelectric motor shaft via a toothed gear mechanism. In technicalswitching terms, there is an advantageous direct effect. Thetransmission mechanism described is no longer needed. The structuralcomplexity is reduced, a further reason for that being that the toothedgear mechanism has a driven gear wheel, the hub of which is passedthrough by the operating shaft. For rotational driving with respect tothe control cam, it is then provided that the operating shaft has apolygonal cross-section. Such an unround polygonal cross-section issuitably a hexagon. Correspondingly or preferably, the hub has aninternal cross-section that is adapted to the polygonal cross-section ofthe operating shaft. It is further realized that the toothed gearmechanism has a worm, which drives the driven gear wheel via step-downintermediate gear wheels. The take-off from the worm can then take placefrom two sides, directly or diametrically offset. This produces anadvantageous force transmission without overloading; the forces on theworm, in the form of counter-directed radial components, cancel oneanother out, as it were. In this case, it is additionally advantageousthat the axis of rotation of the worm is in line with the axis ofrotation of the electric motor shaft. This provides a compactconstruction. In technical switching terms, it is advantageous withregard to the functions of the roller if the operating shaft isdisplaceable in relation to the hub in the longitudinal direction of theoperating shaft of the driven gear wheel. This permits disengagingmovements on the electric motor side with respect to the rotationaldriving, that is to say forms an advantageous basis for performing ordecoupling the functions. A structurally advantageous solution is thenobtained by an operating shaft passing through the control cams of tworollers disposed at a distance from each other. This produces asynchronous operation of neighboring rollers. In order in this respectto reach all four rollers, for example of a chassis of a bed,synchronously in switching terms by simple means, it is proposed thattwo operating shafts which are coupled via a drive mechanism for thesimultaneous switching operation of three or more rollers by an electricmotor are disposed parallel to each other. The corresponding switchingmember may be embodied in the form of a push rod. It is also taken intoaccount in respect of the motor that the fixed electric motor has anelectric motor shaft extending at right angles to the plane of theoperating shaft. The said electric motor shaft generally also determinesthe lengthwise shape of the entire casing, lying in this direction. Thiskind of use, chosen to act like a pointer, is at the same time offundamental significance for additional functions, all the more so sincethe winding region (stator winding) of the electric motor is disposed ahandwidth away from the operating shaft. This gives the electric motorthe status of a handle, in that it is further provided that the casingof the electric motor going over into the winding region is formed suchthat it projects freely in the manner of a handle. Once released, it canbe turned and consequently used as a switching lever for the differentfunctions. It is therefore also advantageous if the electric motor isassociated with an extreme end of the operating shaft. For goodoperating accessibility, it proves to be useful for the electric motorto be disposed, for example with respect to a setup in a hospital bed,on the outside of the bed in relation to a roller. This means theoutline of the bed, or hospital bed, determined by the bed frame. Inorder on the other hand to avoid an exposed position of the electricmotor, it is proposed that the electric motor is disposed with respectto a setup in a hospital bed on the inside of the bed in relation to aroller. Both the mutual association and the step-down referred to alsoallow a function of independent significance, in that the electric motoris disposed rotatably with the operating shaft for emergency operation.In other words: the toothed gear mechanism of the electric motor isself-locking from the driven gear wheel. Performance of emergencyoperation requires deliberate release of the pivotability of theelectric motor. In a corresponding way, secure mounting of the same canbe relinquished for emergency operation. For this purpose, the chassisof the hospital bed is used. This precaution is of such a kind that aspring pin engaging in a fixed bearing bore is provided for fixedmounting. Release is confined to pulling the spring pin, whichconsequently leaves the fixed bearing bore and again enters the fixedbearing bore in the opposite direction, with snapping engagement. Theperformance of the functions of the roller is brought about by means ofsensor-controlled electrical effects. For this purpose, it is providedthat on the operating shaft there are circumferentially distributedposition indicators, which pass contactlessly over a position sensor fordetecting a switching position of the operating shaft. The positionindicators themselves in this case formed as a magnet. The positionsensors, on the other hand, are provided by proximity switches. It isadvantageous here in technical assembly terms if the position sensorsare accommodated in a common circuit board. The highly stepped-downelectric motor allows small, defined angular movements. In view of thefunctions of pivoting blockage (directional fixing), release position,braking and pivoting blockage (total blockage), it is advantageous ifthree position indicators are provided and they are disposed within acircumferential range, covering the entire turning angle, of 180° orless. Furthermore, it proves to be advantageous that two or more,preferably all, of the rollers are intended for joint operation and thateach roller has an associated operating shaft of its own and anassociated electric motor of its own, the operating of the electricmotor taking place via a central control unit, which is in operativeconnection with each of the electric motors. Returning to the positionindicators, it is structurally advantageous for them to be disposed witha spacing from one another over the length of the operating shaft. Thismeans over a relatively short section of the length of the operatingshaft. In terms of how they are associated with one another, in practicea smaller segment of a circle is sufficient, since, according to anexemplary embodiment described below, the three position indicators aredisposed within a circumferential range of 90°, which can even bereduced to 60°. A variant of the means for emergency release is thenalso embodied by the operating shaft having over its length not only anengaging portion, with which the toothed gear mechanism interacts, butalso a release portion and by the operating shaft being displaceable inits longitudinal direction in relation to the toothed gear mechanism, sothat, for emergency operation, the release portion can be brought intoassociation with the toothed gear mechanism. A still more simplesolution is that an extreme end of the operating shaft is provided witha manual operating handle. This engagement takes place in this case bythe operating shaft being axially movable against spring force by meansof the manual operating handle.

[0006] The invention then also relates to a roller according to thefeatures of the precharacterizing clause of claim 1 or in particularaccording thereto, a control device and a storage battery also beingprovided, which solution is characterized in that the power supply tothe control device is switchable by the storage battery and in that,following operation of the roller, to be triggered by means of theswitching device, the switching device completely interrupts the powerconnection to the storage battery. Moreover, it is taken into accountthat, for carrying out an operation of the roller by means of theswitching device, separate activation of the power supply of theswitching device has to be carried out. With activation of the powersupply to the switching device, an indication of the operating state ofthe roller takes place. In this way, the current function is in eachcase perceptible, and correspondingly also the new function. Finally,the invention proposes for the switching units of the switching deviceto be disposed on a common circuit board, which switching circuit boardcan also, optionally, be integrated into an existing switching unit ofthe hospital bed. Finally, it is provided that the position sensors aredisposed with a spacing from one another over the length of theoperating shaft.

[0007] The subject matter of the invention is explained in more detailbelow on the basis of an exemplary embodiment represented in thedrawing, in which:

[0008]FIG. 1 shows, in a perspective representation, a movable hospitalbed using the rollers according to invention, one being fitted with anelectric motor,

[0009]FIG. 2 shows a perspective view from below of one end of thechassis of the hospital bed,

[0010]FIG. 3 likewise shows, in a graphic representation, the electricmotor, associated with a carrier which can be connected to the chassis,

[0011]FIG. 4 shows the carrier on the other side, with a roll, withwhich position indicators are associated,

[0012]FIG. 5 shows a plan view of the associated circuit board, carryingassociated position sensors,

[0013]FIG. 6 shows a vertical section through the roller in the pivotingblockage position,

[0014]FIG. 7 shows the front plate, visually showing this position, of acontrol device in switch operation,

[0015]FIG. 8 shows a section like FIG. 6, showing the release position,

[0016]FIG. 9 shows the front plate, visually showing this position, ofthe control device in switch operation,

[0017]FIG. 10 shows a section like FIG. 6, showing the braking andpivoting blockage of the roller,

[0018]FIG. 11 shows the front plate, visually showing this position, ofthe control device in switch operation,

[0019]FIG. 12 shows the plan view of the roller with the electric motorsecurely mounted,

[0020]FIG. 13 shows a view toward the roller with the casing of the gearmechanism partially broken open,

[0021]FIG. 14 shows a vertical section through the driven gear wheelwith the operating shaft,

[0022]FIG. 15 shows a representation corresponding to FIG. 14 with theoperating shaft disengaged, and

[0023]FIG. 16 shows a drive mechanism transmitting the switching action,schematized to the greatest extent.

[0024] The roller 1 according to the invention is formed as acastor-type roller and is associated with the four corners of atraveling mechanism. In the case of the exemplary embodimentrepresented, this is a chassis 2 of a hospital bed 3.

[0025] The chassis 2 is in connection with a bed frame 5 by means ofcolumn pieces 4. The said bed frame finishes at the head and foot withvertically rising boards 6.

[0026] The bed frame 5 may be divided, so that frame parts can beadjusted and fixed in relation to one another, for example to achievespecific bed profiles (these means are not represented).

[0027] The chassis 2 is assembled from box sections. The box sectionmaterial comprises a beam 7, as a T bar, and arms 8, crossing the latterat the end before the head, comprising the T cross-pieces.

[0028] The rollers 1 are associated with the free ends of the arms 8 bymeans of a horizontally insertable carrier 9. The insertion connectionis reversible and secured by a transverse pin. The insertion projectionhas the reference numeral 10. It is offset by the wall thickness of thebox section and moreover made to match the clear cross-section of thesame, and is therefore directionally stable, i.e. rotationally secured.The shoulder 9′, formed by the wall offset, between the carrier 9 andthe insertion projection 10 acts as an insertion limitation.

[0029] From the underside of the carrier 9 there extends a pivotablymounted wheel fork 11. Axle-mounted on it is a running wheel 12. Thewheel fork 11, with a wheel projection extending to the running surface13, establishes a freely accessible low-level region 14 of the chassis2. The height achieved is sufficient for example for floor cleaningoperations.

[0030] As can be seen for example from FIGS. 6, 8 and 10, the roller 1continues on the upper side into a vertically aligned superstructure 15.Such a roller 1 is the subject of DE-A1 44 12 603 and is to be describedhere to explain the technical functions. Nevertheless, this roller canbe formed in a more compact manner, or this is even the aim, so that thecorresponding mechanism is accommodated in the carrier 9 as a casing(compare for example FIG. 1). The roller is secured by a holding screw.The screw hole in the carrier 9 is revealed in the drawing.

[0031] The roller 1 performing the functions, represented in FIGS. 6, 8and 10, is mounted axially offset vertically with respect to thehorizontal running-wheel axis x, to permit the pivoting movement of therunning wheel 12, or of the wheel fork 11. The vertical axis isdesignated by y.

[0032] Extending from the wheel fork base, in the upward direction, is avertically aligned carrying pin 16. The latter is surrounded by a sleeve17, which is mounted in a receptacle of the carrier 9. They areassociated with each other in such a way as to be rotationally fixed.The casing of the carrier 9 may also itself assume the function of asleeve.

[0033] With a ball bearing 18 interposed, the wheel fork 11 is rotatablewith respect thereto, so that the pivoting movement mentioned of therunning wheel 12 is obtained.

[0034] The upper end of the sleeve 17, optionally directly of thecarrier 9, accommodates a control cam 19 aligned transversely to thevertical. Its center is passed through by an operating shaft 20. Thelatter has a polygonal cross-section. A hexagonal cross-section isrepresented. The passage cross-section 21 of the center is made tomatch, that is hexagonal.

[0035] Inside the hollow carrying pin 16 there is a push rod 22extending vertically, but rotationally secured. It is displaced in thedirection of the running wheel 12 when there is rotational displacementof the control cam 19. This takes place counter to the force of acompression spring 23. The latter acts as a return spring. Thecompression spring acts against a thrust piece 24 screw-connected to thepush rod 22.

[0036] The upper side of the thrust piece 24 terminates with a plate 25.The latter engages the notch-contoured circumference of the control cam19 with a tooth 26. The tooth 26 impinges perceptibly on gaps ofdifferent depths and on a circular arc portion of the control cam 19.Following the contour of the latter, beyond the basic positionrepresented in FIG. 8 there occurs a blockage of the rotational mobilityof the running wheel 12 and/or of the pivoting movement of the runningwheel 12, to be more precise of the wheel fork 11. The stated positionsare respectively defined by the support at the top.

[0037] Between the plate 25 of the described operating device B and thethrust piece 24, loaded by the compression spring 23 in the direction ofthe plate 25, there is a force accumulator, realized as a screw-threadcompression spring, with central thread-adjusting means. This can beused to set the pressing-in resistance of the braking means. However,these means are not the subject of the present patent application. Theyare disclosed in detail by DE-A1 44 12 603.

[0038] At the lower end of the push rod 22 there is a braking device,designated as a whole by 27. To stop the running wheel 12, a brakingpart 28 seated at the lower end of the push rod 22 engages in therunning surface 29 of a flexible tire 30 of the running wheel 12. Youare referred to FIG. 10.

[0039] Serving to block the pivoting movement of the wheel fork 11 is atoothed rim 31, installed behind the braking part 28. The said toothedrim is seated unrotatably on the vertically displaceable push rod 22.Its downwardly pointing teeth 32 act together with tooth gaps 33 of aresilient blocking element 34 of the wheel fork 11, which allows theteeth 32 to spring into the said gaps. Entering these tooth gaps 31, thepivoting movement of the wheel fork 11 is consequently blocked at thesame time as and along with the stopping of the rotational movement ofthe running wheel 12.

[0040] On the other hand, however, the pivoting movement of the wheelfork 11 can also be blocked alone, since the upper side of the toothedrim 31 has blocking projections 35, which can engage in matchingdepressions 36 of the fork base. In this situation, the push rod 22assumes its highest possible displacement position. You are referred toFIG. 6.

[0041] The main element of the operating device B is an electric motor37. The electric motor 37 has a highly stepped-down toothed gearmechanism 38. This mechanism acts directly with the operating shaft 20,which is connected to the control cam 19 in a rotationally fixed manner.

[0042] As FIG. 12 reveals particularly clearly, the electric motor 37acts by means of an electric motor shaft 39 via the toothed gearmechanism 38 on the end there of the operating shaft 20, freelyprojecting correspondingly with respect to the carrier 9. The end, orextreme end, of the operating shaft 20 has the same described polygonalcross-section as the passage cross-section 21. The operating shaft 20 inthis case passes through the solid hub 40, which is axially supported onboth sides, of a driven gear wheel 41 of the toothed gear mechanism 38.The internal cross-section of the hub 40, with a cavity identical to thepassage cross-section 21, has the reference numeral 42. Toward the hub40, this may be, seen in the axial direction, a lying fixed connectionor else a displaceable association with respect to the driven gear wheel41. The latter is preferred.

[0043] The drive element of the electric motor 37 is a worm 43.Associated with the said worm is an intermediate gear wheel 44,correspondingly realized as a worm wheel. Intermediate gear wheel 44acts via a gear wheel 45 of smaller diameter on the driven gear wheel41, which has the greatest diameter.

[0044] The toothed gear mechanism 38 includes the intermediate gearwheel 44 in paired association. The reference numerals are usedanalogously. In a corresponding way, there is also a further worm 43.The direction of the thread of the worms 43 is opposed, that ismaintaining the direction. The intermediate gear wheels 44 perceptiblylie laterally offset from each other, lying on opposite sides of theelectric motor shaft 39. This produces force introduction centers thatare advantageous in terms of loading, since they are distributed. Theelectric motor shaft 39 is supported in an opposing manner at the sides.The step-down ratio is 210:1. The supply voltage is 12 V.

[0045] A gear casing 46, enclosing the internal components of thetoothed gear mechanism 38, follows on to the left in FIG. 12 from thecasing 47 of the electric motor 37. Altogether there is a bar-like basicbody. The main reason for this is the axis of rotation 48 of the worm 43or integral worms 43, which runs virtually in a longitudinally centralmanner and is in line with the axis of rotation 49 of the electric motorshaft 39. The geometrical axes run coaxially and spatially below thegeometrical horizontal axis of the operating shaft 20. Instead ofrunning below the plane of the operating shaft 20, the electric motorshaft 39 may also extend in the plane of the said operating shaft 20.The latter comprises a turning point for the overall electricmotor/toothed gear mechanism body 37/38, projecting freely to the left.The toothed gear mechanism 38 and the electric motor 37 may also beinstalled in a combined casing.

[0046] The electric motor 37, that is substantially the winding region50 of the electric motor 37 (stator and rotor), extends a good handwidth away from the operating shaft 20, at the free end of which theentire unit is coupled on in a rotationally driving manner. The saidcasing-enclosed winding region 50 is of a substantially cylindricalshape that can be grasped by a hand. The casing 47 of the electric motor37, going over into the winding region 50, can consequently be used as afreely projecting handle, so that this permits emergency operation ofthe roller 1 or rollers 1. More details on this follow further below.

[0047] With a view to the handle-forming association, the securing ofthe electric motor 37 at the extreme end of the operating shaft 20 isperformed in such a way that the electric motor 37, aligned in its basicposition in line with the beam 7 and connected to the chassis 2,possesses an alignment extending at right angles to the plane of theoperating shaft 20. This is virtually identical to the electric motorshaft 39.

[0048] Depending on the dimensions of the chassis 2 determining thecorner points with respect to the bed frame 5, the association withrespect to the spatial position of the roller 1 or rollers 1 may be suchthat the electric motor 37 is disposed, for example with respect to asetup in a hospital bed. 3, on the outside of the bed in relation to aroller 1. On the other hand, however, an association such that theelectric motor 37 is disposed, for example with respect to a setup in ahospital bed 3, on the inside of the bed in relation to a roller 1 canalso be used.

[0049] The electric motor 37 can be used to bring about the functionsshown in FIGS. 6, 8 and 10 with the aid of a controller by means ofsensors. A storage battery 51 may serve as the own power source of thehospital bed 3. The said storage battery is carried and mounted on abracket, extending from the beam 7 of the chassis 2. The power lineconnection independent from the supply system is suitably laid by usingthe spaces inside the hollow sections of the chassis 2.

[0050] The associated control device 52 is located on an outer side ofone of the boards 6 of the hospital bed 3. It is likewise carried on abracket, which has the reference symbol 53.

[0051] If the power source fails, for example because the charge of thestorage battery 51 is depleted, the described functions can neverthelessbe performed, in that the electric motor 37 is used as the switchinglever or arm rotationally driving the operating shaft 20. This bringsabout the functionally determining turning of the control cam 19 of theroller 1. This consequently exploits the fact that, indeed for theemergency operation described, the electric motor 37 is disposed withthe operating shaft 20 rotatably on the chassis 2 or carrier 9. A drivengear wheel 41, comprising as it were a screw wrench, of the toothed gearmechanism 38 does not produce reversible running. The step-down ratiodescribed results in a self-locking toothed gear mechanism 39 of theelectric motor 37.

[0052] In order, however, to be able to pivot the pivoting movement,going correspondingly about the geometrical horizontal axis of theoperating shaft 20, of the handle-forming casing 47 of the electricmotor 37, including a portion of the gear casing 46, the deliberaterelease of this pivoting movement going in the direction of the arrow zis required. This is so because, for emergency operation, securemounting of this unit 46/47 first has to be relinquished.

[0053] A structural component of such a secure mounting is a spring pin54 running spatially parallel to the operating shaft 20. The said springpin is mounted in a guiding receptacle 55 of the gear casing 46. It isspatially located in the transitional region between the said casing 46and the casing 47 of the electric motor 37. On the visible side, it endsas a waisted pull knob 56. The spring 57, loading the spring pin 54, isrealized as a compression spring.

[0054] The spring 57 loads the spring pin 54 in the direction of a fixedbearing bore 58 in such a way that it can be overcome for release. Thesaid bore extends congruently with respect to the guiding receptacle 55and is formed in a lateral projection 59 of the carrier 9. The spring 57perceptibly acts against an annular collar 60 on the foot of the springring 54. The spring abutment is located on the inner side, facing thecarrier 9, of the gear casing 46. A recessed annular step may takeeffect here.

[0055] The gap between the carrier 9 and the gear casing 46 that isbridged by the spring pin 54, or its extended shank end, is designatedby 61. This gap 61 is also crossed by the end of the operating shaft 20held rotationally securely by the driven gear wheel 41.

[0056] A securing device for mounting the electric motor/gear mechanismunit in a way preventing it from being pulled off is designated by 62.It can, however, be deliberately detached for disassembly reasons.

[0057] After pulling the pull knob 56, releasing the pivotability of theelectric motor 37, or even before, it is not necessary on account of anadequately dimensioned cable length to disconnect the cable connectionto the electrical equipment, i.e. to disconnect a contact connector 63,the electric cable 64 of which leads to the electric motor or windingregion 50 of the same. The horizontal insertion space formed on thelateral projection 59 has the reference numeral 65. It is connected to aline channel 66, which in spite of the cross-sectionally filling shapeof the insertion projection 10, allows corresponding cable lead-throughsin the interior of the box section of the chassis 2.

[0058]FIG. 3 also clearly reveals that the carrier 9, including theinsertion projection 10, are prepared for drawing in the operating shaft20, to be precise in the form of a horizontal bearing eye 67 with theclear diameter of the point width of the hexagon of the shaft 20.

[0059] Using the power source in the form of the storage battery 51 andthe control device 52, all four rollers 1 can each be fitted with anelectric motor 37 of the type described, including the equipment foremergency operation.

[0060] However, the drawing shows one possibility to the effect that theoperating shaft 20 simultaneously operates two rollers 1, lying next toeach other, of a common arm 8 by means of only one electric motor 37.For this purpose, an operating shaft 20 of a corresponding length passesthrough the control cams 19 of two rollers 1 disposed at a distance fromeach other in the form of castor-type rollers. In a corresponding way,the end of the arm 8 that is remote from the electric motor 37 has acarrier 9 having a bearing eye 67. With regard to the insertionprojection 10, the construction is identical. Otherwise, enhancingmeasures are taken, which are explained further below.

[0061] In order, however, to make all four rollers 1 controllable bymeans of one electric motor 37, the arm 8 at the rear in FIG. 1, i.e.lying on the left side, is also equipped as described. Using the beam 7,a drive mechanism 68 is also formed, comprising a thrust rod 69. Thelatter acts at the end via points of articulation 70 each on a lever arm71 of the operating shaft 20. By means of such a drive mechanism 68, itis accordingly possible, by using two operating shafts 20 forsimultaneous switching operation, to bring three or more rollers 1synchronously into the respective functions by one electric motor 37.

[0062] In the region associated with the lever arm 71, a furthersupporting element with a bearing eye may be provided.

[0063] The carriers 9 occurring in a further version to this extentundertake as it were an adapter function.

[0064] Alternatively, with regard to the emergency operation referredto, it may also be provided that an extreme end of the operating shaft20 is equipped with an operating handle. Such a handle is represented inFIG. 1 and designated by 72. The bearing eye 67 there is correspondinglypassed through outwards. It is comparable to a keyhole. The manualoperating handle 72 is suitably able to be pulled off.

[0065] While here, as it were, an axially fixed operating shaft 20 isassumed, a structurally simple variant of the emergency operation canalso be achieved however by its axial displacement. The relevantoperating shaft 20 is axially loaded by a spring 73. This takes placeover a linear region of a polygonal portion a. The said portion is in arotationally driving connection to the hub 40 of the driven gear wheel41 of the electric motor 37. The functionally correct basic position isshown. If the positive engagement between the parts 20 and 41 is then tobe relinquished, that is a release achieved with respect to the drivemeans of the electric motor 37 in the sense of unlatching, the operatingshaft 20 is displaced counter to the force of the spring 73 to the left.As this happens, the region of the hub 40 is entered by a cylindricalportion b, which in terms of its diameter is less than the size of thewidth across flats of the hexagonal portion a of the operating shaft 20.Therefore, divorced from the self-locking influence of the electricmotor 37, the operating shaft 20 can nevertheless be turned, doing sowhile performing the functions described above via the control cam orcams 19. The polygonal portion c lying to the right of the cylindricalportion b corresponds once again to that designated by a. The polygonalportion c may serve for the engagement of the manual operating handle72, which corresponds in terms of its cross-section. This consequentlyachieves the effect that the operating shaft 20 has over its length notonly an engaging portion, comprising the polygonal portion a, with whichthe toothed gear mechanism 38 interacts, but also a release portion,formed by the cylindrical portion b, and that the operating shaft 20 isdisplaceable in its longitudinal direction in relation to the toothedgear mechanism 38, so that, for emergency operation, a release portion,that is the cylindrical portion b, can be brought into association withthe toothed gear mechanism 38. After pulling this manual operatinghandle 72, the operating shaft 20 moves speedily under spring loadingback into its basic position, which can be seen from FIG. 13. The stopmeans of the operating shaft 20 are not represented, since they caneasily be imagined.

[0066] Now back to the basic version, to take up the matter of thealready indicated electrotechnical equipment: it is based on asensor-controlled electrical fixing of the rollers. These means areaccommodated in the carrier 9 remote from the electric motor 37 (you arereferred to FIGS. 2 and 4). The insertion projection 10, here, too,offset to form a step or shoulder, has been introduced into the end ofthe arm 8 lying at the front on the right in FIG. 1. Seated inside thecarrier 9 are the internal parts of the operating device B describedwith respect to FIGS. 6 et seq., as the main part the control camdesignated by 19. Here, the end region of the operating shaft 20 isextended outward. It protrudes into the interior of an attachment 74,forming a casing, of the carrier 9 concerned. The attachment 74 lies onthe side remote from the insertion projection 10 of the carrier 9, whichitself is basically cuboidal.

[0067] The attachment 74 is open upward and at the extreme end, as wellas at the bottom, so that it is accessible for fitting components, inparticular at the end and bottom. The end opening has the referencenumeral 75. The bottom opening is designated by 76.

[0068] A cylindrical roll 78 can be introduced via the end opening 75into the cavity 77 of the attachment 74. The said roll can be insertedover its entire length. It has, situated in a longitudinally directedmanner in the center, a continuous internal cross-section 79. This iscross-sectionally made to match the cross-section of the end there ofthe operating shaft 20. There is consequently positive engagement with acorresponding rotationally driving effect. The axially correct fixingsuitably takes place by means of a grub screw, the radially directedthreaded bore of which on the roll side is revealed by FIG. 4.

[0069] Consequently, disposed on the operating shaft 20, indirectlyassociated with it, are position indicators 80, distributedcircumferentially on the roll 78. The position indicators 80 are formedas magnets. They are shaped in the form of pins. Their center axes liein radials. To receive the magnets, or position indicators 80, the roll78 has matching pockets 81, opening toward the outer wall.

[0070] Altogether, three position indicators 80 are provided on the roll78, covering the functions mentioned above, such as pivoting blockage(cf. FIG. 6), release position (cf. FIG. 8), braking and pivotingblockage (cf. FIG. 10). An overall rotational angle of the operatingshaft 20 or roll 78 of less than 180° is sufficient for this. Accordingto the exemplary embodiment represented, the three position indicators80 are even accommodated within an overall rotational angle of 90°. Thiscan be reduced still further, for example to 60°.

[0071] The individual position indicators 80 extend in the longitudinaldirection of the operating shaft 20, but also with axial spacing fromone another. The angular spacings between respective position indicators80 in the case of the exemplary embodiment represented are substantially45°, as indicated reducible even to 30°. The position indicators 80,exposed in the manner of cylinders of music boxes, extend virtually onan imaginary helix on the circumference of the roll 78, whilst takinginto account the axial offset.

[0072] The detection plane lies vertically and insects the geometricalaxis of the operating shaft 20.

[0073] An end wall 82 lying opposite the said end opening 75 axially onthe carrier side comprises, with respect to a concentric collar 83 onthe inner side of the roll 78, an axial limiting stop for the actuatingshaft 20 fitted with the roll.

[0074] A stop in the opposite direction, that is counteracting, isobtained on the side of the operating shaft 20 having the electric motor37 by a cap, also playing a part in forming the securing device 62mentioned above. On the other side, facing the carrier 9, of theelectric motor 37, a collar 84 is formed onto the gear casing 46,protruding in the direction of the gap 61. Lying opposite this collar 84is a stub 85 of the carrier 9 there. The shaft 20 is axially secured.

[0075] Locationally fixed position sensors 86 serve for detecting theswitching positions of the operating shaft 20 or the described rollerfunctions. The position indicators 80 pass contactlessly over thesesensors. The position sensors are formed as proximity switches and areaccommodated in a common circuit board 87. You are referred to FIG. 5.The circuit board 87 is shown enlarged there.

[0076] The position sensors 86 are also disposed with axial spacing fromone another over the length of the operating shaft 20. This spacingcorresponds to that of the position indicators 80, only that the formerare linearly positioned only in an axially oriented manner.

[0077] The circuit board 87 shown enlarged in FIG. 5 is associated withthe opening at the bottom, designated by 76, by way of transverseinsertion. The transversely oriented vertical wall portions of thebottom opening 76 have for this purpose longitudinal grooves (notrepresented), which guide, or grasp, the corresponding edges of thecircuit board 87. Securing means may keep the circuit board 87 in theoperationally correct position.

[0078] As already indicated, the power supply to the control device 52takes place by the storage battery 51. In this respect it is taken intoaccount in switching terms that, after operation of the roller 1, to betriggered by means of the switching device, the switching device alwayscompletely interrupts the power supply to the storage battery 51 again.This proves to have a significant energy-saving effect. For thenext-following function, i.e. before carrying out a functionally relatedoperation of the roller 1 by means of the switching device, separateactivation of the power supply to the switching device always has to becarried out. It is also possible in each case here to read the currentfunction, so that the user can see directly whether the function chosenby him has not already been chosen. Consequently, activation of thepower supply to the switching device is accompanied by an indication ofthe operating state of the roller 1.

[0079] Furthermore, it is provided that the switching units of theswitching device/control device 52 are likewise disposed on a commoncircuit board.

[0080] With multiple use of electric motors 37, the configuration isadvantageously such that two or more rollers 1 are intended for jointoperation and that each roller 1 has an associated operating shaft 20 ofits own and electric motor 37 of its own. Here, too, the operation ofthe electric motors 37 follows by means of a central control unit. It isin operative connection with each of the electric motors 37.

[0081] The operating elements of the control device 52, comprisingvarious buttons, are grouped together in a clear layout on its frontplate 88, sloping down like a desk. By operating a button 89, thecontrol device 52 switches into the standby mode. This is indicated by alight-emitting diode 90 (for example green). By means of another button91, the standby mode is switched off again. In FIGS. 6 and 7, thepivoting blockage is switched. For this purpose, a pivoting blockagebutton 92 is pressed. This produces the electrical fixing of thedirection, under sensor control. This is also optically/visuallyperceptible to the side of the pivoting blockage button 92 by alight-emitting diode. FIGS. 8 and 9 show the release position of theroller 1, correspondingly reached under sensor control. For thispurpose, the release button, designated by 93, is pressed. Alight-emitting diode disposed next to it makes this situationperceptible in the way stated. The control cam 19 is movedcounterclockwise. The electrical adjusting drive moves into the positionrepresented.

[0082]FIGS. 10 and 11 show the braking and pivoting blockage. To achievethis total stop, the braking and pivoting blockage button, designated by94, is pressed. Here, too, the optical/visual indication of thisfunction takes place to the side.

[0083] The three functions described can also be manually brought aboutin the event of a fault, by the measures discussed in detail furtherabove. After corresponding unlocking of the electric motor 37, it can bebrought out of its horizontal, freely projecting extent into an anglebisector to the vertical and from there into a vertical position, as itdoes so passing through the respective switching steps.

[0084] As FIGS. 1 and 6 et seq. reveal, the free space necessary for thepivoting operation is provided by an adequate vertical low-level region14. Even a differently directed pivoting movement, that is clockwise, ispossible, since there is adequate free space between the upper side ofthe chassis 2 and the underside of the bed frame 5 as a result of thesuperstructure designated by 15.

[0085] With regard to the storage battery 51, it remains to be notedthat this has an on/off rocker switch, and also a capacitive chargeindicator and a connection for a power supply system connector, so thatthe supply to the control device can also take place by this means.

[0086] The electrics operate extremely economically, since the controldevice switches off after each newly set function.

[0087] All disclosed features are (in themselves) pertinent to theinvention. The disclosure content of the associated/attached prioritydocuments (copy of the prior patent application) is also herebyincorporated in full in the disclosure of the patent application,including for the purpose of incorporating features of these documentsin claims of the present application.

1. Roller (1), in particular a castor-type roller, with the rotationalmovement of the running wheel (12) and optionally the pivoting movementof the running wheel (12) being fixable, with an operating shaft (20)which passes through a control cam (19) of the roller (1) and on whichan electric motor (37) acts via a gear mechanism to operate it,characterized in that the electric motor (37) acts on the operatingshaft (20) by means of an electric motor shaft (39) via a toothed gearmechanism (38).
 2. Roller according to claim 1 or in particularaccording thereto, characterized in that the toothed gear mechanism (38)has a driven gear wheel (41), the hub (40) of which is passed through bythe operating shaft (20).
 3. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat the operating shaft (20) has a polygonal cross-section.
 4. Rolleraccording to one or more of the preceding claims or in particularaccording thereto, characterized in that the hub (40) has an internalcross-section (42) that is adapted to the polygonal cross-section of theoperating shaft (20).
 5. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat the toothed gear mechanism (38) has a worm (43), which drives thedriven gear wheel (41) via step-down intermediate gear wheels (44). 6.Roller according to one or more of the preceding claims or in particularaccording thereto, characterized in that the axis of rotation (48) ofthe worm (43) is in line with the axis of rotation (49) of the electricmotor shaft (39).
 7. Roller according to one or more of the precedingclaims or in particular according thereto, characterized in that theoperating shaft (20) is displaceable in relation to the hub (40) in thelongitudinal direction of the operating shaft (20) of the driven gearwheel (41).
 8. Roller according to one or more of the preceding claimsor in particular according thereto, characterized in that an operatingshaft (20) passes through the control cams (19) of two rollers (1)disposed at a distance from each other.
 9. Roller according to one ormore of the preceding claims or in particular according thereto,characterized in that two operating shafts (20) are disposed parallel toeach other and are coupled by means of a drive mechanism (68) for thesimultaneous switching operation of three or more rollers (1) by oneelectric motor (37).
 10. Roller according to the features of theprecharacterizing clause of claim 1 or in particular according thereto,characterized in that the fixed electric motor (37) has an electricmotor shaft (39) extending at right angles to the plane of the operatingshaft (20).
 11. Roller according to one or more of the preceding claimsor in particular according thereto, characterized in that the fixedelectric motor (37) has an electric motor shaft (39) extending at rightangles in or below the plane of the operating shaft (20).
 12. Rolleraccording to one or more of the preceding claims or in particularaccording thereto, characterized in that the angular range (50) of theelectric motor (37) is disposed a handwidth away from the operatingshaft (20).
 13. Roller according to one or more of the preceding claimsor in particular according thereto, characterized in that a casing (47)of the electric motor (37) going over into the winding region (50) isformed such that it projects freely in the manner of a handle. 14.Roller according to one or more of the preceding claims or in particularaccording thereto, characterized in that the electric motor (37) isassociated with an extreme end of the operating shaft (20).
 15. Rolleraccording to one or more of the preceding claims or in particularaccording thereto, characterized in that the electric motor (37) isdisposed, for example with respect to a setup in a hospital bed (3), onthe outside of the bed in relation to a roller (1).
 16. Roller accordingto one or more of the preceding claims or in particular accordingthereto, characterized in that the electric motor (37) is disposed, forexample with respect to a setup in a hospital bed (3), on the inside ofthe bed in relation to a roller (1).
 17. Roller according to one or moreof the preceding claims or in particular according thereto,characterized in that the electric motor (37) is disposed rotatably withthe operating shaft for emergency operation.
 18. Roller according to oneor more of the preceding claims or in particular according thereto,characterized in that the toothed gear mechanism (38) of the electricmotor (37) is self-locking.
 19. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat secure mounting of the electric motor (37) can be relinquished foremergency operation.
 20. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat a spring pin (54) engaging in a fixed bearing bore (58) is providedfor fixed mounting.
 21. Roller according to the features of theprecharacterizing clause of claim 1 or in particular according thereto,characterized in that on the operating shaft (20) there arecircumferentially distributed position indicators (80), which passcontactlessly over a position sensor (86) for detecting a switchingposition of the operating shaft (20).
 22. Roller according to one ormore of the preceding claims or in particular according thereto,characterized in that the position indicators (80) are formed as amagnet.
 23. Roller according to one or more of the preceding claims orin particular according thereto, characterized in that the positionsensor (86) is formed as a proximity switch.
 24. Roller according to oneor more of the preceding claims or in particular according thereto,characterized in that the position sensors (86) are accommodated in acommon circuit board (87).
 25. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat three position indicators (80) are provided and they are disposedwithin a circumferential range, covering the entire turning angle, of180° or less.
 26. Roller according to the features of theprecharacterizing clause of claim 1 or in particular according thereto,characterized in that two or more rollers (1) are intended for jointoperation and in that each roller (1) has an associated operating shaft(20) of its own and an associated electric motor (37) of its own, theoperating of the electric motors (37) taking place via a central controlunit, which is in operative connection with each of the electric motors(37).
 27. Roller according to one or more of the preceding claims or inparticular according thereto, characterized in that the positionindicators (80) are disposed with a spacing from one another over thelength of the operating shaft (20).
 28. Roller according to one or moreof the preceding claims or in particular according thereto,characterized in that the three position indicators (80) are disposedwithin a circumferential range of 60°.
 29. Roller according to thefeatures of the precharacterizing clause of claim 1 or in particularaccording thereto, characterized in that the operating shaft (20) hasover its length not only an engaging portion, with which the toothedgear mechanism (38) interacts, but also a release portion and in thatthe operating shaft (20) is displaceable in its longitudinal directionin relation to the toothed gear mechanism (38), so that, for emergencyoperation, the release portion can be brought into association with thetoothed gear mechanism (38).
 30. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat an extreme end of the operating shaft (20) is provided with amanual operating handle (72).
 31. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat the operating shaft (20) is axially movable against spring force bymeans of the manual operating handle (72).
 32. Roller according to thefeatures of the precharacterizing clause of claim 1 or in particularaccording thereto, a control device (52) and a storage battery (51) alsobeing provided, characterized in that the power supply to the controldevice (52) is switchable by the storage battery (51) and in that,following operation of the roller (1), to be triggered by means of theswitching device, the switching device completely interrupts the powerconnection to the storage battery (51).
 33. Roller according to one ormore of the preceding claims or in particular according thereto,characterized in that, before carrying out an operation of the roller(1) by means of the switching device, separate activation of the powersupply of the switching device has to be carried out.
 34. Rolleraccording to one or more of the preceding claims or in particularaccording thereto, characterized in that, with activation of the powersupply to the switching device, an indication of the operating state ofthe roller (1) takes place.
 35. Roller according to one or more of thepreceding claims or in particular according thereto, characterized inthat the switching units of the switching device are disposed on acommon circuit board, which switching circuit board can also,optionally, be integrated into an existing switching unit of thehospital bed (3).
 36. Roller according to one or more of the precedingclaims or in particular according thereto, characterized in that theposition sensors (86) are disposed with a spacing from one another overthe length of the operating shaft (20).